Low Resistivity Titanium Nitride Thin Film Fabricated by Atomic Layer Deposition on Silicon

A low temperature (300°C–350°C) TiN thermal ALD process using titanium tetrachloride (TiCl
4
) and anhydrous hydrazine was developed to yield films with resistivities below 200 μohm-cm. Surface treatments such as Ar plasma and atomic hydrogen were applied to further reduce the surface impurities including all halogens. These experiments indicate that minimizing oxygen concentration using an ultra-clean ALD process with minimum background oxidants and high purity precursors are keys in producing TiN thin films with low resistivity.